Dry low emission (DLE) engines may need to maintain nitric oxide and nitrogen dioxide (NOx) and carbon monoxide (CO) emissions below a specific level to satisfy requirements of certain regulating agencies. Failure to maintain the emissions under these limits may result in financial penalties or even force the operator to take a DLE engine out of service. Controllers can modulate staging valves and compressor bleeds of a DLE engine as a function of flame temperature schedules. These flame temperature schedules can be mapped and saved to ensure regulatory requirements for emissions are met.
However, when there are changes in ambient conditions, fuel sources, and/or minor damages in engine components, the flame temperature schedules may not result in an acceptable behavior of a DLE engine. A mismatch of flame temperature schedules and operational conditions may result in combustor flameouts and engine trips.